1. Field of the Invention
The invention is directed to a mechanism for declutching a direct drive crawler by depressing the decelerator pedal.
2. Description of the Prior Art
Many work vehicles, such as crawler dozers and loaders, are provided with fluid drives for transmitting rotational speed and torque from the engine to the gear train of the final drives. One type of fluid drive is a torque converter which acts as a clutch connecting and disconnecting power between the engine and gear train, and as a transmission providing a greater number of speed ratios. Hydrostatic transmissions are another type of fluid drive that directs rotational torque from the engine to the gear train of the final drives.
In inching or slowly moving a work vehicle close to an object, an operator of a torque converter work vehicle controls the movement of the vehicle through a decelerator pedal. The decelerator pedal controls the output of the engine and therefore the amount of rotational torque and speed being applied to the torque converter. When the decelerator pedal is completely depressed, the vehicle can be stopped, without stalling the engine, by depressing the brake pedal.
Direct drive work vehicles are more efficient than torque converter vehicles, however the operator needs to manipulate three pedals when operating in close quarters. More specifically, fully depressing the decelerator pedal does not declutch the engine from the gear train. To get close to an object, the operator first depresses the decelerator pedal to slow the vehicle. Then the operator depresses the clutch pedal to declutch the engine and prevent stalling the vehicle, and depresses the brake pedal to stop the vehicle.